Heretofore, a honeycomb structure which is made of cordierite and onto which a catalyst is loaded has been used in a treatment of harmful substances in an exhaust gas emitted from a car engine. Additionally, it is known that a honeycomb structure formed by a silicon carbide sintered body is used in purification of the exhaust gas.
In a case where the exhaust gas is treated by the catalyst loaded onto the honeycomb structure, it is necessary to raise a temperature of the catalyst up to a predetermined temperature, but there has been the problem that at start of the engine, the catalyst temperature is low and hence the exhaust gas is not sufficiently purified.
To eliminate such a problem, there has been reported a honeycomb structure in which a pair of electrode members are disposed on a side surface of a honeycomb structure onto which a catalyst is loaded, and heat is generated in the honeycomb structure by performing energization between this pair of electrode members, so that the honeycomb structure also functions as a heater (e.g., see Patent Document 1).